The present invention relates to fire-resistant containers; more particularly, to fire-resistant safes; and most particularly, to a fire-resistant safe comprising both insulative and intumescent materials.
Containers for temporarily protecting their contents from damage from external heat sources such as fire are well known. Such containers are said in the art to be xe2x80x9cfire-resistantxe2x80x9d and typically are rated for integrity over a specific exposure temperature and/or time. Lockable fire-resistant containers are known as fire-resistant xe2x80x9csafesxe2x80x9d and are widely used for storage of documents, firearms, or other valuables which may be damaged or destroyed by exposure to high temperatures. For example, various models of fire-resistant safes are available from Sentry Group, Rochester, N.Y. 14625 USA.
A common problem encountered in some inexpensive prior art so-called fire-resistant safes is that they may include some fire-resistant or fire-rated materials such as gypsum board or drywall, but they do not pass the stringent explosion and fire endurance tests found in Underwriters Laboratories Standard 72, parts 1 and 2. Part 1 requires a container to maintain an internal temperature of less than 350xc2x0 F. while the container is thermally ramped up a prescribed time-temperature curve from room temperature to 1550xc2x0 F. over 30 minutes. Part 2 requires a container to protect paper from decomposing or igniting in a simulated explosion condition of instantaneous external temperature of 2000xc2x0 F. for 20 minutes.
One approach to meeting these requirements in the prior art is to provide a container having relatively thick walls and large mass. Such a safe is expensive to manufacture, costly to purchase, and cumbersome to transport.
What is needed is a fire-resistant safe which is inexpensive to manufacture, easy to transport, and meets the requirements of Underwriters Laboratories Standard 72.
It is the primary object of the invention to provide an improved fire-resistant safe for storage of documents, firearms, or other valuables which is inexpensive to manufacture, easy to transport, and meets the requirements of Underwriters Laboratories Standard 72.
The invention is directed to a fire-resistant container for use as a safe. The container is formed of steel and is lined on its inner surface with fire-resistant materials. The preferred fire-resistant materials include both mineral wool insulation, to retard the passage of heat into the interior of the container, and hydrated fiberboard to swell and thereby seal the container while undergoing progressive dehydration and intumescence. Preferably, an air space is also provided between the fire-resistant materials and the wall. A front wall of the container is formed with an offset jamb for receiving a safe door having a conventional combination lock controlling a plurality of livebolts which are received in bolt cups formed in the jamb. The door is fitted with fire-resistant materials in similar fashion to the container walls, and the jamb is gasketed in intumescent material. Within the container, an inner wall is formed of a fire-resistant material such as gypsum board. A fire-resistant container in accordance with the invention meets Underwriters Laboratories Standard 72 and is suitable for storage of paper documents, firearms, and other valuables.